To date, presence and availability capabilities have been confined generally to instant messaging systems such as Microsoft Messenger and ICQ. Users are presented with availability information in the form of buddy lists from which they are able to see which ones of their corespondents are available and attempt to send an instant message to them. The instant message system attempts delivery but there is no ability, such as is provided by call control in a telephony system, to forward the call to another party, take a message, etc. Thus, no solution has been provided in the prior art to the problem of missed calls due to party unavailability.
To be truly useful, availability information must be as current and accurate as possible. In emerging IP telephony systems, where availability information is provided, the indicators of availability are primarily set by the user. The user can set his/her availability to ‘At Lunch’, ‘Be Right Back’ etc. This is obviously deficient in the sense that it relies on user action, which may be deferred when the user is concerned with other immediate pressing issues or more commonly when he/she is simply distracted. This often leads to a situation wherein users do not use the such availability notification features since they are not updated often enough to be useful, and they are not updated often enough to be useful because people will not use them.